Fluid control system and controller and moisture sensor therefor

ABSTRACT

A fluid control system (and controller and moisture sensor therefor) having one or more latching solenoid operated pilot control valves and a master control unit for controlling the valves. The valves utilize a concentric arrangement of the major components thereof, each being coaxially located with respect to a single housing member. The control electronics may be battery operated and may locate with respect to one valve to provide drive signals to control one or more valves in sequence. The control electronics utilizes an oscillator such as a crystal oscillator with a chain of count down flip-flops to provide binary signals up to a period of preferably twenty-four hours or more. A manual selection is provided to select among the longer period signals to control the frequency with which the operating cycle is initiated, with a second manual control being used to select one of the lower frequency signals to control the duration for which each valve will remain open. Logic is provided so that only one valve will be open at any one time thereby providing for sequential rather than simultaneous operation of a group of valves during each watering cycle. Alternate embodiments utilizing light sensitive controls are also disclosed.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to the field of fluid control systems, andmore particularly to the field of automatic sprinkler systems.

2. Prior Art

The present invention is primarily directed toward use as an automaticsprinkler system and component parts thereof, and thus the followingdiscussion of the prior art shall be so limited. In particular, thepresent invention comprises primarily a unique configuration for a pilotcontrolled valve and a unique system, including control electronics, forutilizing the valve to achieve a highly accurate, very reliable and lowcost automatic sprinkler control system. Thus the prior art relating topilot actuated valve configurations and control systems, and moreparticularly battery operated control systems is most relevant to thepresent invention.

Most prior art sprinkler valves and systems for automatic operationwhich are presently in use are intended for driving by a common 110 V.60 Hz. power, typically through a mechanical time clock and step downtransformer. Such systems have a good reliability, and at least thecomponent parts thereof may be manufactured at a reasonable cost.However, typically installation is very expensive for new homes, and maybe prohibitive in established homes because of the necessity of runningsome form of electrical line under sidewalks, lawns, trees and the like.Accordingly, in recent years various designs for battery operatedsprinkler control systems have been proposed which effectively eliminatethese otherwise severe installation problems.

One such prior art batteery operated system is that of U.S. Pat. No.3,821,967. This type of system uses a latching actuator to control apilot valve to actuate a main valve member cooperating with a valveseat, typically already in the sprinkler line, such as the valve seatassociated with the manual valve portion of an anti-siphon valve. Thelatching actuator and pilot valve assembly is mounted to the side of themain actuator assembly so as to control the venting of water from thetop to the bottom of the pressure responsive member (a diaphragm in thespecific patent referred to). The entire system is turned on by a pulsederived from a crystal oscillator and count-down chain, with the systembeing turned off by a unijunction time delay circuit initiated by theturn on signal. Additional units in a group of units may only have theunijunction time delay circuit therein, with each such unit having aprovision for receiving an initiating signal to trigger the opening ofthe valve, and to provide an initiating signal to the next valve uponits closing. This, together with the providing of an initiating signalwith the closing of the valve having the crystal oscillator therein,allows for the sequential operation of an unlimited number of valves,based upon a single crystal oscillator input. Thus, each valve in such achain comprises not only the valve but in addition at least a time delaycircuit and power supply to operate the latching actuator, with thefirst unit in the chain also having the master time clock comprised of acrystal oscillator and count-down chain.

The foregoing system has a number of advantages. In particular,installation is very easy, the crystal oscillator is very accurate, andbattery life is relatively long. In addition only one master oscillatoris required for any group of valves, and yet sequential operation mayreadily be achieved by a simple interconnection of adjacent valves toprovide sequential operation for maximum use of normally limited watersupply delivery rates. Such a system, however, has certain disadvantagesalso. In particular the maximum watering time achievable by unijunctionoscillators using components of reasonable cost is limited, and thewater duration is not very accurate unless calibrated. In addition thevalve mechanical configuration and the design and arrangement of thelatching actuator and pilot mechanism are not of the simplest design,resulting in a larger number of parts than necessary, and havingsensitivities to adjustments requiring assembly and test time. As aresult, the design of the foregoing patent, while solving a great numberof problems of the prior art, is not a low cost design, is limited inwatering duration achievable and the accuracy of the watering durationselected.

Another type of battery operated sprinkler system is that disclosed inU.S. Pat. No. 3,547,154. That system uses a battery to operate a motordriven timer which periodically rotates a permanent magnet on a timerdisc into proximity with a magnetically actuated read switch, whichturns on a solenoid valve and a time delay network, which in turn turnsoff the solenoid valve after the desired time. This system is rathermechanically and electronically complex and requires relatively largebatteries, such as wet storage cells. It further has no provision foroperating a plurality of valves in sequence from a single timer. Whilevarious specific valve configurations are known for use in such systems(see U.S. Pat. Nos. 3,460,798; 3,785,612; 3,858,841; 3,412,970;3,410,301; and 3,363,433) such valves are mechanically complex andconsume too much power for battery operation. Thus there is a need forvalves for fluid control system which are mechanically simple andinexpensive to manufacture, and which consume a minimum of power so asto be suitable for battery operation.

BRIEF DESCRIPTION OF THE INVENTION

A fluid control system (and controller and moisture sensor therefor)having one or more latching solenoid operated pilot control valves and amaster control unit for controlling the valves. The valves utilize aconcentric arrangement of the major components thereof, each beingcoaxially located with respect to a single housing member. These majorcomponents include the valve closure member, the pilot valve, thediaphragm separating the high and low pressure areas, and the latchingactuator controlling the pilot valve. A mounting flange member isprovided for threading into a valve body, and is in turn threaded to thevalve body member so that the entire valve assembly may be rotated muchlike a conventional valve handle to provide a flow control, and a manualshutoff if desired. The control electronics may be battery operated andmay locate with respect to one valve to provide drive signals to controlone or more valves to provide signals to control one or more valves insequence. The control electronics utilizes an oscillator such as acrystal oscillator with a chain of count down flip-flops to providebinary signals up to a period of preferably twenty-four hours or more. Amanual selection is provided to select among the longer period signalsto control the frequency with which the operating cycle is initiated,with a second manual control being used to select one of the lowerfrequency signals to control the duration for which each valve willremain open. Logic is provided so that only one valve will be open atany one time thereby providing for sequential rather than simultaneousoperation of a group of valves during each watering cycle. Alternateembodiments utilizing light sensitive controls are also disclosed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a system utilizing the present inventionvalves and controller, complete with moisture probe;

FIG. 1a is a cross-section of the moisture probe of FIG. 1;

FIG. 2 is a partial cross-section of a typical valve of the system ofFIG. 1 illustrating the valve in the closed condition;

FIG. 3 is a partial cross-section of a valve and electronic controllerillustrating the valve in the open position;

FIG. 4 is a cross-sectional view of member 48 of FIGS. 2 and 3;

FIG. 5 is a cross-section taken along line 5--5 of FIG. 3;

FIG. 6 is a cross-section taken along line 6--6 of FIG. 2;

FIG. 7 is a partial cross-section taken along line 7--7 of FIG. 6;

FIG. 8 is a top view of a portion of the top cap of a typical valve;

FIG. 9 is a partial cross-section taken along line 9--9 of FIG. 6;

FIG. 10 is a schematic diagram illustrating the wiring of the solenoidin the preferred embodiment;

FIG. 11 is a top view, partially cut way, of the electronic controllerof FIG. 1;

FIG. 12 is a circuit diagram of the battery power supply for theelectronic circuit;

FIG. 13 is a schematic for the electronic circuit of the controller ofFIG. 1;

FIG. 14 is a schamatic for an alternate controller;

FIG. 15 is a schematic for a circuit for disabling the controller duringdaylight hours;

FIG. 16 is a circuit for disabling the controller during hours ofdarkness; and

FIG. 17 illustrates a split connector for providing overlapping orstaggered operation of the valves.

DETAILED DESCRIPTION OF THE INVENTION

First referring to FIG. 1, a perspective view of a typical installationutilizing three valves operated from a common battery operatedcontroller may be seen. The valves 21 replace the manual valve portionof antisiphon valves 23. One of the valves, namely the left valve, has acontrol package mounted thereon. The control package 25, which isbattery operated, operates not only the valve on which it is mounted,but further is coupled through leads 27 the other two valves in thesystem illustrated so as to operate all three valves in sequence. Thevalves themselves however are identical, and in that regard the controlpackage 25 may be mounted on any of the valves, and the valves may beoperated in any sequence desired. Also shown in FIG. 1 isa moisturesensor 29 coupled to the controller 25 through a line 31.

Now referring to FIG. 2, a partial cross-section of the basic valveassembly of the present invention may be seen. This embodiment of thevalve assembly is intended to replace the manually operated valve onconventional valve bodies, and may also be used in conjunction withconventional anti-siphon valves commonly used in sprinkler systems as areplacement to the manually operated valve portion thereof. Thus, amounting member 20 is provided with the valve assembly for threadinginto a valve body, such as the anti-siphon valve body 22. A housing 24containing the mechanism of the pilot-operated valve has a downwardextending smaller diameter portion 26, which at the lower end thereofmates with threads 28 in the mounting member 20. An O ring 30, locatedin a cooperatively disposed groove in the downward extending portion 26,provides the desired sealing between member 26 and the mounting member20.

One of the features of the present invention may be noted in thestructure so far described. In particular, it will be noted that thelower portion 26 of the housing 24 threads into mounting member 20without any fixed limit or locating shoulder, and accordingly, thehousing 24 and the entire assembly therein may be rotated to screw theassembly further into or out of the mounting member 20. This allows oneto manually close the valve, and provides an adjustable flow control forthe valve when in the open position. A snap-ring 32 locates in acooperatively disposed snap-ring groove adjacent to the bottom of member26, below the bottom of the mounting member 20, so as to prevent theinadvertent unscrewing of the valve assembly from the mounting member.

A valve actuating member 34 extends downward through the lower portion26 of the housing 24 to support a valve closure assembly comprisingsupport member 36 and a complaint rubber washer 38, which in conjunctionwith the seat 40 on the valve portion of the anti-siphon valveduplicates the function of the manual valve normally supplied with theanti-siphon valve assembly. The support member 36 has an upwardextending section 42 extending within the end of the valve actuatingmember 34, with a smaller further upward extending section 44 slidingwithin a mating internal diameter of the actuating member. An O-ring 46is disposed in the groove defined by the combination of the supportmember 42 and the valve actuating member 34, which provides a fluid sealbetween these two members and further serves the additional functions offrictional retention of the two members (the support member and thevalve actuating member) in cooperative relationship and of providingsome slight swivel effect between these two members so as to allow therubber washer 38 to align and fit flat on the valve seat 40 as shown inFIG. 2 to assure positive valve closure.

Washer 38 is retained in position with respect to the support member 36by a flanged member 48, details of which may be seen in FIG. 4. Thismember has a lower flange 50 and upward extending cylindrical section 52for slidably fitting within a mating inner diameter on the supportmember 44, and a further upward extending section 54 defining first andsecond opposed spring-like members 56 at the upper end thereof. Member48 also has a concentric opening therethrough defined in part by asmallest diameter 58 at the lower end thereof. The flanged member 48slides through the inner diameter of the support member 36 with theupward extending spring-like member 56 snapping outward over the upperend of the support member to retain the support member, the rubberwasher and the flanged member in assembled disposition. Thus, it will benoted that this entire assembly may be readily removed from the lowerend of the valve actuating member 34 by merely pulling it off againstthe frictional restraint of the O-ring 46. This allows the quickreplacement of the assembly with a different assembly to fit valves ofother sizes or dimensional characteristics, and further allows the quickreplacement of the rubber washer 38 if such replacement is everrequired. It will be noted that all such replacement may beaccomplished, once the valve assembly is off the valve body, without anytools such as screwdrivers and the like, thereby minimizing thepossibility of damage to any of the plastic parts of the valve.

Adjacent the upper portion of the valve actuating member 34 are fourequally spaced key-like projections 60 around the periphery of the valveactuating member (only two being visible in FIG. 2). These key-likemembers slidably engage cooperatively disposed slots or reliefs 62 inthe inner surface of the downward extending portion 26 of the housing24, so as to freely allow relative axial motion while preventingrelative rotation therebetween. At the upper end of the valve actuatingmember 34 is a flange-like protrusion 64 having a provision forreceiving the inner diameter 66 of a rubber diaphragm 68, with alock-nut 70 threadably engaging the upper end of the valve actuatingmember to lock the inner surface of the diaphragm in this assembly. Theouter periphery of the diaphragm 72 is retained between a support member74 and a pilot valve member 76. The pilot valve member 76 in conjunctionwith the diaphragm 68 defines an upper chamber 78 which, whenpressurized, will tend to encourage the valve actuating member to thelower position. A lower chamber 80 below the diaphragm is inconnumication with the low pressure side of the anti-siphon valve 82through the annular region 84 between the valve actuating member 34 andthe lower portion 26 of the housing 24.

The pilot valve member 76 has a central downward protruding portion 86having an opening 88 therethrough, with a valve seat 90 at the top ofthe opening 88. A rubber diaphragm 92 may be encouraged to the downwardposition by a pilot valve actuating member 94 so as to abut the valveseat 90 and close off the opening 88. The upper portion of the diaphragm92 has a radially outward extending flange terminating with anO-ring-like periphery 96 sealing within a cooperatively disposed groovein a separator member 98. A pressure plate 100 is supported on aplurality of legs 102 so as to force the O-ring-like periphery 96 of thediaphragm 92 into good sealing abutment with the separator plate 98while at the same time allowing water flow thereunder in a manner whichwill be subsequently described. The separator plate in turn is selaedagainst water leakage around its periphery by an O-ring 104 disposedbetween the separator member and the housing 24. Below the downwardextending protrusion 86 of the pilot valve member is a rod 106 having anenlarged end 108 abutting the lower surface of protrusion 86 and havinga transverse slot 110 at the upper end thereof so as to allow fluidcommunication between the opening 88 and the region 112. The rod 108 isencouraged upward to the position shown by the coil spring 114 which inturn is retained against downward motion by the inward projectingshoulder 116 adjacent to the lower end of the valve actuating member 34.Accordingly, the coil spring 114 also encourages the valve actuatingmember to the lower position with a force sufficient to override anycontrary elastic encouragement of the valve actuating member by thediaphragm 68, though totally insufficient to itself hold the valve inthe closed position (valve actuating member down) against anysignificant pressure in the high pressure side of the valve 118.

With the pilot valve closed, that is, diaphragm 92 resting on valve seat90 on the pilot valve member 76, the low pressure chamber region 80 isvented to the low pressure or downstream side 82 of the valve. The upperor high pressure chamber 78, on the other hand, is in communication withthe high-pressure or inlet side of the valve 118 through the annularflow regions immediately surrounding pin 108 and the downward protrusion86 of the pilot valve member 76. Consequently, as the valve closuremember moves downward against the pressure in the inlet line 118, thissame high pressure of the inlet line is communicated to chamber 78 abovethe diaphragm and, since the diaphragm and associated moving structurehas an area exceeding the area enclosed by the valve seat 40, theactuating member will move downward to the position shown in FIG. 2against the inlet pressure in line 118 to close the valve and retain thevalve in the closed position. (Initially, when the valve is open, thepressures in regions 82 and 118 may be nearly equal in which case thepressures above and below the diaphragm will also be nearly equal. Inthis case, the coil spring 114 will initially encourage the valveactuating member and associated assembly downward to start the closingsequence, with the differential pressures generated during closingtaking over to complete the closing regardless of any reasonablepressure in line 118.)

Now referring to FIG. 3, the valve may be seen in the open position. Theseparator member 98 has an integral outward-extending periphery 120abutted from above by the core 122 of a solenoid actuator, with the core122 and separation member 98 defining a region therebetween forcontaining the moving member 124 of the actuator. The moving member 124is normally encouraged to the lowermost or downward position by a coilspring 126, which in turn pushes the member 94 to the lower position bya drive pin 128 projecting through a cooperating hole in the separatormember 98. This forces the diaphragm 92 against the valve seat 90,closing the pilot valve as shown in FIG. 2. However, when the actuatoris actuated as shown in FIG. 3, the pilot valve is opened and, as shallbe subsequently described, the region above the diaphragm is effectivelyvented to the region below the diaphragm, thereby equalizing thepressures and allowing the pressure in the inlet line 118 to force thevalve actuating member to the open position. Thus, with the pilot valveopen, the fluid above the diaphragm may flow over the top members 70 and34, and between legs at the top of these two members provided for thispurpose. This flow path continues between the inner diameter of thevalve actuating member 34 and the outer diameter of the downwardprotrusion 86 on the pilot valve member, through the slot 110 and thepilot valve, and upward around the diaphragm 92, between the legs 102 onmember 100, outward through enlarged slots in the top of member 76,through an annular region 130, slots 75 provided for this purpose,through an annular region 132 and finally between legs at the bottom ofmember 74 provided for this purpose. This flow path is made particularlynonrestrictive in comparison to the restriction provided by the annularflow region between rod 106 and member 48 so that the pressures on thetwo sides of the diaphragm can nearly equalize, independent of thepressure differential between the inlet line 118 and the outlet region82 on the valve body. Accordingly, this differential pressure isresisted only by the force of coil spring 114, a relatively minor force,so that the valve is forced to the open position by the pressure in theinlet region 118 to allow flow therethrough.

It will be noted that in the previous description, all the variouscomponents of the valve assembly, including the valve actuating memberand associate components, the pilot valve and the actuator, aresubstantially coaxially arranged. In addition, it may be noted that theonly subassembly which is separately retained is that of the valveactuating member 34, diaphragm 68 and retaining nut 70, with all of theadditional various parts hereto described which are located within thehousing 24 being merely a stacked assembly ultimately retained under acompressive force resulting from the fastening of the top cap 140 ontothe housing 24, which in the preferred embodiment is achieved throughthe use of self-tapping screws. The "wet" portion of the assembly, thatis, the lower housing assembly, is sealed with respect to the actuatorby the O-ring 104 and diaphragm 96 (FIG. 2) with the actuator region inturn being sealed from the external environment in party by the O-ring142.

It should be noted also that the angular orientation of the variousparts, except for the valve actuating member 34 with respect to thedownward extending portion 26 of the housing 24, is not restricted. Inparticular, where the flow passageways in some parts must be incommunication with similar flow passageways in adjacent parts, annularreliefs are generally provided in one of the parts between thepassageways so that peripheral fluid flow in the annular relief willcompensate for the random angular orientation of the parts. By way ofspecific example, the annular region 130 between pilot member 76 and thehousing 24 (FIG. 2), assures proper flow between the passages defined inpart by the pilot valve member 76 and the support member 74. (A similarannular passage 144 is provided between member 100 and the pilot valvemember 76.)

Now referring to FIGS. 2, 6 and 7, details of the actuator, andparticularly the electrical connection thereof may be seen. The actuatorof the preferred embodiment is basically that of U.S. Pat. No.3,743,898, and more specifically an actuator comprising one-half of thedual actuator of FIG. 8 of that patent. This type of actuator ischaracterized by a stationary magnetic member 122, a moving magneticmember 124 and a magnetizing coil or coils 200. By maintaining the airgap at substantially zero when in the actuated position, very little MMFis required to maintain the actuator in that position, and aself-latching effect is attained even with magnetic members of lowretentivity. When the field strength is reduced as the result of ademagnetizing current in coil 200, the force between the moving member124 and the stationary member 122 falls in proportion to the square ofthe flux density, so that the return spring 126 may force the movingmember 124 to the downward position, thereby closing the pilot valve asshown in FIG. 2.

Now referring to FIG. 10, a schematic illustration of the electricalconnection of the solenoid coil 200 in each valve may be seen. The coilconsists of two sections separated by a tap 204, with end leads 202 and206. Line 204 in the ultimate interconnection represents a common line,with a pulse on line 202 providing magnetization of the magnetic circuitin a first direction to actuate the solenoid and latch it in the closedposition. A pulse of lesser current magnitude between line 206 and thecommon of the same polarity causes a magnetizing field in the oppositedirection, and if properly limited results in substantialdemagnetization of the magnetic path, thereby allowing the return spring126 to force the actuator to the lower or extended position to close thepilot valve. A switch 208 is shown in FIG. 10, disposed between the offinput lead 210 and the lead 206 of the coil which switch in practice isprovided by the mechanical and electrical contact between the movingmember 124 and the stationary member 122 when in the closed position,and the absence of such contact when in the open position, as shown inFIG. 2. Thus lines 202 and 204 are wired directly to two of theelectrical connections 202a and 204a on the valve (see FIG. 8), with thethird connection 210a being coupled to lead 206 on the coil 200 througha center contact 212, coil spring 126, moving member 124 and finallystationary member 122.

In the preferred embodiment the stationary member 122 is not a fullcircular member, but instead the sides are truncated symmetrically sothat a portion of the coil 200 extends beyond the sides of the member,allowing the various leads thereof to freely pass upward between aplastic member 214 and the top cap 140. Member 214 has three slotsacross the top surface thereof (FIGS. 6 and 7) to receive and locate thethree wires 202, 204 and 206 from the solenoid coil. For two of theleads, specifically leads 202 and 204, member 214 contains pockets inthe central section of the slot for receiving the leads in which a metalspring member 216 is located. These metal spring members each encouragethe respective lead down, forcing the spring member into direct face toface abutment with a contract pad 218 riveted through an appropriateopening in the top cap 140 and to an electrical terminal of some form onthe top of the top cap. In the preferred embodiment the contacts orterminals 202a and 204a (FIG. 8) are male and female terminalsrespectively of the type commonly used on the conventional nine volttransistor batteries so as to provide a quick disconnect capability witha mating connector.

For the third lead 206 a slightly different arrangement is used, as maybe seen in FIG. 9. In particular, the pocket containing the spring clip216a extends all the way through the member 214 so that the spring clip216a forces the lead 206 into electrical contact with the stationarymember 122 of the actuator. Also the lead 206 is forced into good faceto face abutment with the spring clip by the plastic top cap 140, sothat all electrical connections are made within the valve withoutrequiring soldering. The integrity of the seal of the enclosure ismaintained by the use of rubber washers 218 (FIG. 7) which seal each ofthe terminal openings. The top cap itself is held on by a plurality offlat self-tapping screws extending through the cover and into holesprovided in regions 220 of the valve housing 24 (FIG. 6).

Now referring again to FIG. 3, some of the details of the controlpackage may be seen. The control package has a bottom mounting plate 300having three contacts 302 riveted through the base plate 300 and havinga combination of male and female connections so as to snap ontoterminals 202, 204 and 210 of any of the valves, though only with theproper connections. The base plate 300, a substantially rectangularplate as may be seen from FIG. 11, extends beyond the edges of the topplate 140 on the valve and has thereunder an additional plurality ofterminals 304 of the same general type for coupling to additional valvesthrough appropriate cables, as may be seen from FIG. 1. In the preferredembodiment the riveting of the various terminals 302 and 304 in positionthrough the base plate provides internal contacts for coil springs 339coupling the contacts to the circuit board. The circuit board itself isheld down by cover 308 at locations not showing in the cross-section ofFIG. 3, with screws in the corner regions and outside the periphery ofO-ring 310 holding cover 308 to the base plate 300.

The printed circuit board 306 supports a pair of rotary switches, one ofwhich may be seen in the FIG. A cover 308 encloses the circuit board andcircuit thereon sealing about its periphery with the base plate 300 byway of O-ring 310. The cover 308 in addition includes an integralreceptacle 312 for batteries covered by member 314, with a protectivecap 316, covering the switches and batteries, having a hinge 318 toallow the lifting of the cap to obtain access to the switches andbatteries. A top view of the cover 308 may be seen in FIG. 11; its mainappearance characteristic being that of the two rotary switches 320 and322. In particular, rotary switch 320 is used to select the wateringtime (the length of the time each valve will remain open). Thus in thepreferred embodiment a minimum duration of approximately forty-twoseconds is available, with increasing durations of approximately one andone-half, eleven, twenty-two and forty-five minutes, and one andone-half, three, six, twelve and twenty-four hours being attainablethrough the switch 320. (As will be subsequently seen, however, otherlines are also possible.)

The rotary switch 322 is used to select the watering period orfrequency. In the preferred embodiment the selections are providedbetween three hours and eight days, in increments separated by factorsof two. In addition, there are provided certain additional positions,including an off position which disconnects the clock from the driverelectronics, a cycle reset position which resets the clock to zero, andan extra cycle position which will cause an extra watering cycle.

The circuit of the preferred embodiment may be seen in FIGS. 12 and 13,with FIG. 12 providing the circuit for the battery power supply and FIG.13 providing a circuit for a five station controller; that is, acontroller which will operate up to five valves of the present inventionautomatically and in sequence.

The supply of FIG. 12 includes four batteries, three 11/2 volt pen lightbatteries 303 (see FIG. 3) providing 41/2 volts for operating theoscillator and other parts of the control electronics, and a 221/2 voltbattery 305 for providing the main drive power for operating theactuator. In order to be able to provide a high current pulse to eachactuator when required, while still protecting the battery, the 221/2volt battery is connected to an RC network comprised of resistor 400 andcapacitor 402. In this manner the resistor 400 limits the current drawnfrom the battery, whereas the capacitor 402 stores sufficient charge todeliver a current pulse at VRD of a substantial fraction of an amp forthe required ten to twenty milliseconds. Also, it will be noted thatdiodes 307 are provided to protect the batteries against reverse flow.Thus, an external supply may be connected to terminals 309 as asubstitute power source, or as a primary source with or without thebatteries as a backup supply. The external source and batteries areisolated from each other by diodes 311 and 313, with resistor 315 beinga current limiter, and resistors 317 acting as a limiter and voltagedivider for the lower voltage supply VLD.

The circuit of FIG. 13 may be functionally described as follows: Acrystal oscillator provides a reference frequency which is count-downthrough flip/flop chains to provide a selection of pulses, ranging fromapproximately forty-two seconds to twenty-four hours for the wateringtimer, and a further longer period series of pulses ranging from threehours to eight days for the cycle timer. The cycle timer pulse is usedto initiate a form of counter, which then is advanced through its countin steps determined by the watering timer pulses, after which it locksup awaiting the next cycle timer pulse (or a pulse received by rotatingthe cycle timer 322 [FIG. 11] to the extra cycle position). As this lastcounter steps through its count the outputs thereof are passed throughRC networks to provide pulses of controlled duration to pulse onDarlington drivers to provide six pulses, starting at the timedetermined by the cycle timer, and having a time duration between pulsesdetermined by the watering timer selection. The first pulse is used toturn on the first valve, with successive pulse turning on the next valveand turning off the previous valve, until the final stage turns off thelast valve in the sequential chain.

To accomplish the foregoing a crystal oscillator is provided comprisingthe crystal and associated network 404, and a crystal driver 406. In thepreferred embodiment an RCA COS/MOS crystal driver identified by theirpart number CD 4045 is used, with the crystal network being selected inaccordance with the manufacturer's recommendations as is well known inthe prior art. The crystal frequency is selected so that the crystaldriver 406, which includes a twenty-one stage count-down chain, providesan output pulse rate of one pulse per forty two seconds on line 408.This pulse is used as the forty two second water timer pulse and inaddition is provided to the input of an additional fourteen stagecount-down chain 410, which in the preferred embodiment is an RCA binarycounter identified by their part number CD 4020. This providesadditional longer period output pulses, with the pulses to twenty fourhours being used for the additional watering timer outputs orselections, and with the pulses ranging from three hours to eight daysbeing used for the cycle timer. A pair of NOR gates 412 and 414 havetheir inputs biased positively or to the high state by resistors 416 and418. In the preferred embodiments these NOR gates are RCA's part number4001, with the two inputs to the gate 414 being tied together so as tooperate as an inverter. It will be noted that the output of the wateringtimer selection switch 320 (see also FIG. 11) is coupled through acapacitor 420 to one input of the NOR gate 412 as well as to the inputof NOR gate 414. The output of the cycle timer selector switch 322 onthe other hand is coupled through a coupling capacitor 424 and aresistor 422 to the second input of NOR gate 412. Since resistors 416,418 and 462 (high value resistors) normally encourage the input to theNOR gates 412 and 414 to the high state, a positive going pulse on theoutputs of either the watering timer or the cycle timer will onlyencourage these inputs to a still higher state, whereas the negativegoing transition of the outputs of the watering timer and cycle timerwill drive the inputs to the low state. Accordingly, the outputs for theNOR gates 412 and 414 are normally in the low state. However, uponoccurrence of a negative going transition from the watering timer, theoutput of NOR gate 414 will be pulsed to the high state with a pulsewidth determined by the time constant of capacitor 420 and resistor 416,and upon the simultaneous negative transition of both the watering timeroutput and the cycle timer output, the output of NOR gate 412 will alsobe pulsed positive, again with the pulse width dependent upon the timeconstants of the input signal conditioning RC network.

The output of the NOR gates 412 and 414 are applied to a series offlip/flops 426, 428, 430 and 432. In the preferred embodiment theseflip/flops are comprised of a pair of RCA dual D-type flip/flopsdesignated by their part no. CD 4013 (the numerical designations withinthe boxes representing the flip/flops, as well as in the count downchain 410 and a crystal driver and count down chain 406, represent themanufacturer's pin designations for the specific part numbers identifiedherein as being used in the preferred embodiment). The data input lineon the first flip/flop 426 is coupled to the positive terminal of the41/2 volt power supply, and therefore the Q output from terminal 1 offlip/flop 426 will go to the high state upon a pulse on terminal 3 (theoutput of NOR gate 412). This acts as the initial enabling pulse, as theoutput of NOR gate 412 is pulsed only once each time the cycle timerprovides an output pulse (for reference in the description to follow,terminals 5 and 9 are the data terminals; terminals 6 and 8 are the setterminals; terminals 4 and 12 are the reset terminals; terminals 3 and11 are the clock input terminals; terminals 1 and 13 are the Q outputterminals and terminals 2 and 10 are the Q terminals).

For purposes of explanation, assume that every two days each sprinklervalve is to be turned on for 3/4 of an hour. Accordingly the wateringtimer adjustment 320 will be set for forty five minutes and the cycletimer will be set on two days. With these settings, the output of NORgate 414 will pulse positive every forty five minutes, and once everytwo days the output of NOR gate 412 will also pulse positive. Initially,all the flip/flops are the low state (Q low, Q high). The output of NORgate 412 is coupled to the clock input of flip/flop 426 and the setinput of flip/flop 428. Since the data input to NOR gate 426 is coupledto the 4.5 volt supply, once every two days the Q output of flip/flop426 is clocked to the high state and the Q output of flip/flop 428 isset to the high state. This change in the Q output of flip/flop 428 iscoupled to the data input of flip/flop 430, and the Q output offlip/flop 428 is coupled through line 434 and capacitor 436 to one ofthe amplifiers 438. Since the Q output of flip/flop 428 changes from thehigh state to the low state, a negative going pulse is coupled toamplifier 438. The resistor 442 in conjunction with the couplingcapacitor 436 provides an RC time constant for this pulse so that theinput to the amplifier is a negative going pulse of limited width, inthe preferred embodiment a pulse of approximately 20 milliseconds. Theamplifiers 438 are actually inverting amplifiers, and more particularlyin the preferred embodiment comprise an RCA hex buffer/converter havingtheir part number CD 4049. Thus, the negative going pulse on the inputto the amplifiers 438 provides a positive going pulse output for drivingthe base of the Darlington pair 440a, thereby coupling terminal 202a toground for a period of approximately 20 milliseconds (see also FIG. 5for the identification of the actuator leads 202, 204 and 210, whichdesignation is continued with respect to FIG. 12, though with a lettersuffix to distinguish between a plurality of valve drivers and valves).Since terminal 204a (the common terminal) is coupled to the positiveterminal of the 221/2 volt supply, the full voltage on capacitor 402 ismomentarily applied to the actuator coil, thereby drawing the movingmember into close face to face abutment with the stationary member andmagnetizing the magnetic circuit so that the retentivity, thoughreasonably low, holds the moving member in the actuated position. (Diode444 protects the Darlington pair from an otherwise high back EMF of theactuator when the Darlington switch is turned off at the end of thepulse.)

At the same time the Q output of flip/flop 428 is coupled through line445 and associated circuitry to the fourth amplifier 438, and since itis inverted therein, provides a negative going pulse to the base ofDarlington pair 440d. Because of the negative going pulse however, theDarlington pair is not turned on, and accordingly only the first driver(Darlington pair 440a) is pulsed on.

After forty five minutes another pulse is received from NOR gate 414which clocks the flip/flop 430 to the set position. Since the negativegoing Q output of this flip/flop is inverted by the amplifiers 438 andcoupled to the base of Darlington pair 440b, a pulse is received to turnon the second valve through terminal 202b. Also a current limitingresistor 446 is coupled to this terminal to provide a current limitedoutput on terminal 210a, which turns off the first valve. After stillanother forty five minutes flip/flop 432 will trigger Darlington pair440c in substantially the same manner to provide a turn on pulse for thethird valve on terminal 202c and a turn off pulse for the second valveon terminal 210b. In addition, the positive going transition of the Qoutput of the flip/flop 432 is coupled back to the reset terminal 4 offlip/flop 426, thereby resetting the flip/flop to change the Q output tothe low state. Accordingly, in the following three forty five minuteintervals, flip/flops 428, 430 and 432 are successively clocked to thereset condition, with the negative going Q output pulses thereof beingused to trigger the Darlington pairs 440d, 440e and 440f, respectively.All flip/flops now are in the same state as initially, awaiting the nextpulse output from NOR gate 412 to start the sequence over again.

Aside from initiating the sequential operation hereabove described, anoutput from NOR gate 412 is also coupled back through line 452 andthrough NOR gates 454 and 456 to reset the count down chain 410. As inthe example previously given, every two days a pulse is received fromthe output of NOR gate 412 to initiate the watering sequence and resetthe countdown chain to start counting for the next two day cycle. Itwill be noted that the second input to NOR gate 454 is biased to the lowstate by a resistor 458 so that with respect to a pulse on line 452,both NOR gates 454 and 456 act as invertors, thereby providing thepositive going reset pulse to flip/flop chain 410 upon the appearance ofa positive going pulse output of NOR gate 412. A similar clock resetpulse however, may be derived by rotating the cycle timer 322 to thecycle reset position. Since line 460 is biased to the high stated byresistor 462, which is a lower resistance than resistor 458, the secondinput to NOR gate on 454 on line 464 is driven to the high state,thereby resetting flip/flop chain 410. Accordingly, the clock is set byrotating the cycle timer 322 to the cycle reset position at the time oneof the watering cycles is desired. By way of specific example, if it isdesired for the watering sequence to be initiated at 7:00 A.M. everyother day, the cycle timer is momentarily rotated to the cycle resetposition at 7:00 A.M., and then turned to the two-day position,whereupon the desired watering sequence will occur every other day at7:00 A.M. Also, of course, any number of valves up to five may be usedwith the circuit of FIG. 13, as the proper operation of the circuit doesnot depend upon valves actually being coupled to all outputs of thecircuit. Finally, it will be noted that an extra cycle position isprovided for the cycle timer 322. When the cycle timer is rotated tothis position the high state on line 460 is coupled to capacitor 461,which in combination with resistors 463 and 465 provides a pulse on line466 is set flip/flop 426. Thus, on subsequent pulses from NOR gate 414,the flip/flops 428, 430 and 432 will be clocked through the variousstates hereinbefore described. Accordingly, the extra cycle position onthe cycle timer will cause an extra watering sequence starting at thenext pulse from the watering timer 320. (Resistor 467 is for testpurposes and resistor 469 is a current limiting resistor.)

It will be apparent from the foregoing explanation that the circuit ofFIG. 13 may be expanded to operate additional valves in sequence bymerely adding additional flip/flops and driver circuits, or that thecircuit of FIG. 13 may be reduced to provide a single valve controllerby eliminating flip/flops 430 and 432 and the associated driver circuitsand merely coupling the output on line 446 back to the reset input forflip/flop 426.

It should be noted that in the embodiment hereinbefore described, thewatering time ranges from approximately forty-two seconds to twenty-fourhours, with most increments being a factor of two from the adjacentincrements. However, there is a substantial jump from 11/2 minutes to 11minutes, a consequence of the specific outputs of the 4020 flip/flopchain. This combination is utilized in the preferred embodiment,however, because watering times up to twenty-four hours are sometimesdesired in agricultural and commercial applications. Another embodimentfor home sprinkler systems eliminates some of the switch positions,thereby providing a maximum watering time of 11/2 hours. As a furtheralternate, however, a 4040 may be used in place of the 4020, incombination with a lower frequency crystal to provide uniform binaryjumps throughout the selected range. However, it is important to notethat other watering increments, such as the three minute and six minuteincrements, not appearing on the watering timer, may be obtained withthe embodiment disclosed. In particular, it will be noted from FIG. 13that an ON signal is achieved on terminal 202a at the initiation of awatering cycle, and after each selected time increment thereafter one ONsignal and one OFF signal is generated by the circuit, terminatingfinally in one OFF signal on terminal 210e. Accordingly, by way ofspecific example, assume the circuit of FIG. 13 were desired to be usedwith two valves to be operated in sequence, with each valve being ON forthree minutes. This may very easily be achieved by connecting the ONterminal 202 of the first valve to the ON signal 202a of FIG. 13 and theOFF terminal 210 of the first valve to the OFF terminal 210b (ratherthan the OFF terminal 210a) and setting the selector to 11/2 minutes.Accordingly, the first valve will turn on immediately, but will onlyturn off after the equivalent of two 11/2 minutes watering periods, orthe desired three minutes. Similarly, the second valve will operate insequence for three minutes by using terminals 202c and 210d. Such aninterconnection, even for the valve on which the electronics is mounted,may readily be achieved by a suitable spacer connector which brings outthe OFF terminal 210 for connection as desired to the additional OFFterminals around the periphery of the control electronics.

Further, if desired, overlapping and staggering of the operation of thevalves may be achieved, again even utilizing watering times notavailable on the watering timer. By way of specific example, assume thewatering timer is set on 11/2 minutes. If the first valve is turned ONby the signal on terminal 202a and turned OFF by the signal on terminal210c, with the second valve being turned ON by the signal on terminal202c and turned OFF by the signal on terminal 210e, each valve willoperate for a period of 41/2 minutes, an operating period not simplyavailable by the watering timer. Furthermore, after three minutes ofoperation of the first valve, the second valve will come on, providingfor simultaneous operation for 11/2 minutes before the first valve shutsoff, which might be desired in certain situations to provide someoperation of a sprinkler system at reduced pressure due to the increasedflow. Other examples utilizing some pause between the operation of twoor more valve, or unequal watering times, will also become apparent fromthe foregoing explanation. To achieve any of these results on a valveother than the one on which the controller is mounted, a split connector800 may be used as shown in FIG. 17, so that separate connections forthe ON and OFF signals at the controller are possible. For the valveunder the controller, a space plate under the controller is used so asto couple out the OFF signal for separate connection as desired to anyof the other OFF signals.

Now referring to FIGS. 1, 1a, and particularly FIG. 13, an additionalhighly advantageous feature of the present invention may be seen. Thatfeature is the moisture probe 29 and the associated circuitry in thecontrol electronics 25. In particular, the probe 29 as illustrated inFIG. 1A is simply a device for providing first and second electrodessubstantially at ground level (or penetrating the ground). In theparticular embodiment of probe shown in the FIGURES, a simple plasticmember having a cup-like top region 700 and a three lobed downardprotruding spike 702 is provided. A central cavity 704 is also providedwhich is vented to the surrounding earth between the lobes in thedownward protruding spike 702. A pair of pins 702 are integrally moldedinto the probe so as to receive a simple connector 708 having the samefemale connectors 710 hereinbefore described with respect to theelectronics and the valves. Basically, when the ground is wet, theresistance between the two connectors 710 will be relatively low as aresult of the water standing in the cup region 700, whereas when theground is merely slightly damp or dry there will be a substantially opencircuit between the connectors 710, and thus between the two probe leadsidentified in FIG. 13 as leads 712 and 714. (Both leads 712 and 714connected to the lower outer edge of the control package are of the sametype of connector as previously identified.) If desired, depending uponthe type of control sought, earth, sand or other moisture absorbingmaterials may be disposed in the cup 700 to make the probe moresensitive to small amounts of moisture in the ground, or direct groundpenetrating probes may be used.

The operation of the probe may be easily understood with reference toFIG. 13 and the description relating thereto. In particular, it waspreviously pointed out that the basic initializing signal allowing thesequential operation of the valves is received on line 322 from thecycle timer selection switch. Normally without the moisture probe thissignal is coupled to capacitor 424 and resistor 422 to activate NOR gate412. However, when the resistance between leads 712 and 714 drops to apredetermined value, indicating conductivity between the two probeterminals (connectors 710) caused by moisture on the probe, the loadcreated on line 712 will alternate the input to NOR gate 412 below thethreshold value of the gate. Thus, flip/flop 426 will not be initiatedand the count down chain 410 will not be reset. In effect resistor 422and the resistance of the probe act as a moisture sensitive variablevoltage divider, which if selected in conjunction with the threshold ofthe NOR gate 412 will achieve the desired result at the desired moisturelevels. In the preferred embodiment suitable results are achieved withresistor 422 having a resistance of approximately 4.7K ohms. The neteffect of this arrangement is that the sprinkler system is substantiallytotally automatic, coming on at predetermined intervals forpredetermined times, except during rainy periods when no watering isdesired. Also it should be noted that the moisture probe does notrequire any significant power or additional circuitry, as its effect isonly to attenuate a very short pulse, if and when called upon to do so.

Now referring to FIGS. 15 and 16, still further features which may beachieved in the present invention may be seen. In particular, in certainsituations it may be desired to water during the hours of darkness onsome predetermined schedule, but to not continue the watering scheduleinto the daylight hours. Thus, as shown in FIG. 15, a simplephotoconductor 716 may be coupled between the two leads 712 and 714.During periods of darkness the resistance of the photoconductor 716 isvery high, thereby not interfering with the operation of the system,which may include the moisture probe if desired. However, duringdaylight hours the resistance of the photoconductors 716 drops grosslyso as to disable the electronics in much the same way as hereinbeforedescribed with respect to the moisture probe.

In FIG. 16 a simple modification is shown which allows operation duringthe daylight hours but disables the system at night. In particular, aphotovoltaic device 718 is used to charge a capacitor 720 in accordancewith the intensity of the light being received. Normally the voltages onlines 712 and 714 are equal (both being +4.5 volts) so that diode 722 isback biased and decouples the voltage across capacitor 720 from thelines 712 and 714. When an initiating pulse is received, however, thevoltage on line 322 swings towards ground, thereby encouraging voltageon line 712 to drop. This voltage may drop by an amount determined bythe forward conduction voltage drop of diode 722 and the voltage oncapacitor 720. Since the forward conduction voltage drop on diode 722 isless than the threshold voltage of NOR gate 412, the circuit will notoperate unless there is a substantial voltage across capacitor 720(assuming capacitor 720 is substantially larger than the couplingcapacitor 424 of FIG. 13).

Thus during daylight hours circuit operation is enabled by the fact thatthe photovoltaic device will receive solar energy and charge capacitor720 accordingly, so that the voltage across the capacitor 720 incombination with the forward conduction voltage drop of the diode willexceed the threshold voltage of the gate 412. However, the circuit willbe disabled at night because the capacitor 720 will have zero or nearzero voltage thereon. Again, as with respect to FIG. 15, this lightsensitive circuit has no substantial effect on the operation of themoisture probe during periods when the circuit is enabled, therebyallowing the use of the moisture probe in conjunction therewith.(Suitable photoconductors and photovoltaic devices are well known in theprior art and may be readily selected by one skilled in the art toachieve the desired results. Also it should be noted that the circuitsof FIGS. 15 and 16 are exemplary circuits only, illustrating the greatflexibility of the electronics design and the various unusual functionswhich may be achieved with the present invention without requiring anysubstantial power from the batteries, achieved simply by the use of apulse rather than a continuous drive on the related sensors.)

Now referring to FIG. 14, a block diagram of an alternate form ofelectronic control may be seen. In this system a photodiode 500 is backbiased by the 41/2 volt supply through a resistor 502. When the lightintensity received by the photodiode increases on sunrise to apredetermined trigger level, the voltage at junction 504 rises to thetrigger voltage of a Schmidt trigger 506 to turn on an oscillator 508and provide a pulse to the RC network comprising capacitor 510 andresistor 512 to start the counter 514. It will be noted that the pulseappearing on line 516 through capacitor 510 and resistor 512 is a pulsesimilar to the enabling pulse from NOR gate 412 in FIG. 13, whereas thepulse train received from oscillator 508 on line 518 is equivalent tothe watering timer pulses received from NOR gate 414. Accordingly, thecounter 514 of FIG. 14 may be substantially identical to the flip/flopchain comprised of flip/flops 426, 428, 430 and 432 of FIG. 13, with theamplifiers and drivers 520 of FIG. 14 being comprised of the amplifiers438 and Darlingtons 440, and associated circuitry of FIG. 13.Accordingly, the photodiode, Schmidt trigger and oscillator of FIG. 14replace the crystal oscillator and count down chains of FIG. 13, andprovide one watering cycle each morning. By using a CMOS Schmidt triggerand a high impedance photodiode network, the current drain may bemaintained at a level consistent with long battery life. Also, byproviding an adjustable shroud over the photodiode 500, the effects ofnearby lights may be minimized, and the extent of sunlight required tooperate the circuit may be varied so that the operation of two or moresuch devices may be suitably staggered in time, e.g., caused to occur atdifferent times during sunrise. The watering duration may be madevariable by providing a variable oscillator for oscillator 508, andadditional watering cycles may be initiated manually during the day byblocking the light from photodiode 500 for a short period, dependentupon the RC time constant of resistor 502 and capacitor 522. (Capacitor522 prevents the operation of the circuit on a momentary blockage of thelight, and the hysteresis of Schmidt trigger 506 avoids multipleinitiation of the circuit caused by fluctuations in the light around thethreshold level). Of course simple inversion of the input or output ofthe Schmidt trigger would result in operation of the system on sunsetrather than sunrise.

There has been described herein a new and unique pilot controlled valvewhich is very simple to manufacture and assemble, which provides veryhigh reliability and long life operation, and which may utilize asolenoid actuator isolated from the fluid regions of the valve toprovide operation at very low power levels. While other forms ofactuation of the pilot valves may be utilized, the preferred embodimentutilizes a solenoid actuator, and more preferably a simple magneticallylatching solenoid actuator operative on simple turn ON and turn OFFpulses. In the preferred embodiment substantially all of the majorfunctional parts of a valve are simply stacked in the valve housingwithout regard to angular orientation, and retained in functionaldisposition by a simple cover retained on the housing by self tappingsscrew. All plastic parts may be molded without requiring secondaryoperations, and the actuator parts may be made by powder metallurgytechniques.

The control electronics is preferably operated by a crystal oscillatorwith a suitable chain of count down flip/flops to provide highlyaccurate timing for both the watering frequency and the watering times,utilizing selections of various outputs of the count down chain. Byproviding discrete ON signals and OFF signals, various combinations ofoperating cycles may be achieved, even obtaining watering times notavailable from the count down flip/flops. By coupling one of theinitiating pulses to a moisture probe, operation may be disabled duringrainy spells automatically. Alternate embodiments have also beendisclosed which initiate on sunrise or sunset, or which disable onsunlight or darkness, all of which alternate embodiments may alsoutilize the moisture probe if desired. While only one specificembodiment of the pilot controlled valve has been described in detailherein, other embodiments of the valve may also be built for stand aloneuse, or use in other systems. By way of specific example, a simple ACsolenoid may be incorporated so that the valves may operate utilizing aprior art mechanical time clock system. As a further alternate,mechanical operation of the pilot valve actuating member may be utilizedstill retaining the basic coaxial arrangement of the primary pilot valveparts so as to achieve a simple mechanical pushbutton valve. Thus whilecertain specific embodiments of the present invention have beendisclosed and described in detail herein, it will be obvious to thoseskilled in the art that various changes in form and detail may be madetherein without departing from the spirit and scope of the invention.

We claim:
 1. A sprinkler system comprising:a plurality of valves, eachof said valves having means responsive to electrical drive controlpulses to open and close the valves; a controller having first andsecond controls, said controller being a means for repetitivelyproviding a train of drive control pulses on a plurality of controllerterminals, at intervals determined by said first control in accordancewith a desired watering frequency, said drive control pulses in eachpulse train being separated in time as determined by said second controlin accordance with a desired watering time; and means for coupling saidcontroller terminals to said plurality of valves.
 2. The system of claim1 wherein each of at least some of same drive control pulses areprovided on a pair of said controller terminals, said drive controlpulses on said pair of said controller terminals having predeterminedlydifferent electrical characteristics.
 3. The system of claim 2 whereineach of said plurality of valves is a pilot operated valve, each of saidpilot valves being controlled by a magnetically latching solenoidactuator.
 4. The system of claim 3 wherein one of said drive controlpulses of predeterminedly different electrical characteristics is apulse of predeterminedly limited current output, whereby one pulse maybe used to latch an actuator and one pulse may be used to unlatch anactuator.
 5. The system of claim 4 wherein said means for coupling saidcontroller terminals to said plurality of valves is a means for couplingsaid controller terminals to said plurality of valves in any desiredorder.
 6. The system of claim 1 further comprised of means coupled tosaid controller for disabling said drive control pulses upon theoccurrence of a predetermined condition external to said controller. 7.The system of claim 6 wherein said means for disabling said drivecontrol pulses is a light sensitive means.
 8. The system of claim 6wherein said means for disabling said drive control pulses is a moistureprobe.
 9. The system of claim 1 wherein said controller and saidplurality of valves have cooperatively disposed means whereby saidcontroller may be mounted to any of said valves.
 10. A sprinkler systemcomprising:a plurality of pilot operated valves, each of said valveshaving a magnetically latching solenoid actuator for controlling thepilot valve therein; a controller, said controller having referencemeans for providing a reference frequency, first counting means forcounting down said reference frequency to provide a plurality ofsubfrequencies of said reference frequency, first selection means forselecting one of a first predetermined group of said subfrequenciesdependent upon the desired watering time, second selection means forselecting one of a second predetermined group of said subfrequenciesdependent upon the desired frequency of the watering cycle, secondcounting means enabled by the output of said second selection means foradvancing through a predetermined count at a rate determined by saidfirst selection means, first output means coupled to said secondselection means for providing a first drive signal for turning on afirst valve upon the occurrence of a change in output from said secondselection means, and additional output means, each of said additionaloutput means being a means for turning on a valve and turning off avalve responsive to subsequent outputs from said first selection means,respectively, the last said output means being a means for turning off avalve upon the still subsequent output from said first selection means;and means for coupling said output means to the solenoid actuator ineach of said plurality of valves.
 11. The system of claim 10 furthercomprised of a conductivity probe means for providing an electricalcharacteristic responsive to the moisture in the ground, saidconductivity probe means being a means for preventing the operation ofsaid second counting means upon the occurrence of a predeterminedelectrical characteristic from said conductivity probe means.
 12. Thesystem of claim 10 wherein the enabling signal coupled to said secondcounting means from said second selection means is a pulse signal, andwherein said conductivity probe is a means for providing an electricalload on said last named pulse signal to alternate said signal responsiveto the moisture sensed by said conductivity probe.
 13. The system ofclaim 10 further comprised of a light sensitive means for preventing theoperation of said second counting means upon the occurrence of apredetermined light condition.
 14. The system of claim 10 wherein saidoutput means are means for providing solenoid actuating pulse ofpredetermined pulse width.
 15. The system of claim 10 wherein saidcontroller and said plurality of valves have cooperatively disposedmeans whereby said controller may be mounted to any of said valves.